I like how you pointed out the times Rey actually communicated with Taani, how he approached her first, was concerned for her well being and even apologised for his behaviour. That is indeed true. Rey has been direct and upfront with Taani in the past. That did change when Shivam was in the picture. But even during that time he did acknowledge his mistakes on a couple of occasions...apologised and post Shivam drama he actually enquired about Taani and once again showed concern. But Taani has made things easier for Rey since she is a girl with no hang ups or ego issues. She has always been willing to accept Rey even with his shortcomings.
Now the complete breakdown of communication was straight after their first intimate moment. Although both of them were living in the moment and were well aware of what was going on...the confusions once again crept in. Both were trying to figure out what the other one was thinking...and sometimes when you over-analyse others you end up confusing yourself! That is the case with Rey and Taani.
Rey tried to dig deep into Taani's thoughts to know how she felt abt that particular moment but she was unable to formulate her thoughts into words. Obviously she didn't think it was a mistake but Swayam's words were clouding her judgement (even though he was speaking in a completely different context) Taani's reaction ticked off Rey and to an extent I don't really blame him. He assumed that his actions would speak for itself and that Taani should understand. His frustration is understandable. However, he did reject her pretty badly and no matter how much things have changed between them, Taani is a very delicate soul. She wants reassurance and that's something he is not understanding.
The beauty of Rey's character is that one minute he can erupt like a volcano...and the next he will be as calm and still as water. He can go to two extremes!